Range finder



June 1 1926.

J. B. HENDERSON RANiGE FINDER Filed July 26, 1919 ZSheet-Sheet 1 l w -11 q mum w w Q 1 flttoriz ya June 1 ,1926. 1,586,741

J. B. HENDERSON RANGE FiINDER Filed July 26, 1919 2 Sheets-Sheet 2 {\1 'o N [W 3 s: N 1 A: N N

. B/ 9122/5 11ft rneya am 1.... 1, 192a.

UNITED STATES PATENT OFFICE;-

i m mm nxnmiaasomior m, i I

a uam ma July so, 1010, Seriallo. 818,589, and in Great Britain mi as, me am mu m rnovmons or mac-r or men a, 1921, 41 1,1318.

My invention has for its object the provision of am improved single-observer" range finder for use ona ship or other moving platfornywhich will materially assist the observer to keep the instrument laid on a target when the ship is rolling and pitching, by automatically compensating the effects of the angular motion of the ship upon the field of view.

Hitherto it has been proposed to mount finders and other optional apparatus on movable plaftforms such as shipguvlvith she interposition o gyroseopic or pen um evices whereby the range-finder orthe like is stabilized to a line of sight unimpaired b a the motion of the platform.

Accor g to this invention I stabilize V someorall of the optical parts such as for example, the prisms, instead of stabilizing the range-finder as a whole, by linking sai parts to a long period pendulum gyroscopic or otherwise, and I introduce a hand adjust ment by which. said arts which are stabil ized may be moved r atively to the stabiliz device.

1 04 illustrate one method of applyin" m invention to a range-finder of the sing eo rver type.

1 shows an elevation of the range finder in part section my gyroscopic attachment applied to it. ,v

2lshows a cross section of the range finder tube and of the gyroscopic attachment on the line AB, the telescope tube being removed from the range-finder.

Figure 3 shows a sectional plan of the gyroscopic-attachment on the line G-D.

Figure 4 showsa sectional lan of the end of the range-finder tube-to s owthe prism' holder-and its supports.

In the range-finder tube 1 is supported by. the two rings 2 on the top of the r twoelimbsjofthe fork 3 which is'pivotally mounted'on pedestal 4, so that the range finder-may-beztrained in azimuth.

.' The inner: telescope tube 5 of the range- 'finder the two objectives, the two eyepiece and the range'adjusting gear which aie not shown and do not form part of my invention.- The doubly reflectipzfi' prisms 6 of -whichthere are two, one at ea end of thebase, are normally fixed to the i ho; r" 1' one me I 0 'ap ymg my lllVQIltlOll I mount each-of pn ms 6 and its prism holder 7 on a short shaft 8 (Fig. 4) pivoted on two ball bearings 9 and 10in a conical pro ection 11 formed on the end cap 12 of therange-findertube 1. Each shaft 8 carmes a spur wheel 13 and the two spur gear wheels with pinions-l i keyed to a long shaft 15. (F lgure 1) which'is mounted on-bearings 16 on the tube 1. The shaft serves to fix the relative elevation of the two prisms 6. I provide an adjustmentto alter this relatlve elevation of the two prisms, that is the halving adjustment of the range finder, by making the teeth of the spur gears 13+14 helical and to make the adjustment I move one of the shafts 8 axially along the range-finder tube by screwing the conical carrier 11 in or out of the tube L I stabilize the two prisms 6 preferably by means of a gyroscope whose case 17 1 and 3) is supported, with the rotor axis approximately vertical, on trunnion bearings 18 on a horizontal gimbal 19 the trunnions 20 of which are pivoted m hearings on two plates 21 and 22 each of which is bolted to the fork 3 by two bolts 23 and 2d (Figure 2) the two plates b rigidly connected at the bottom by the l iir i gge piece 25 which also serves to carry the hinge 26 (F' e 2) of the two half covers 27 and 28, an at the top by the two angles '25 and 25".

The trunnion '20 of the gimbal ring 19 has keyed toit a spurwheel or sector 29 (Figures 1 and 2) of the same itch di- 7 ameter as the spur wheel 13 and Eris spur gears with a spur pinion 30'keyed to the shaft 15. The method of keying the sector 29 to the trunnion 20 is peculiar. The key consists of a roller 31 on the upper end of a short pillar 32 fixed to the gimbal ring 19. The roller 31 engages in a. helical slot 33 {Figure '3) cut in the periphery of adrum 34 bolted to the toothed sector 29. The toothed sector and gimbal ring can turn freely on the hearings in the plates 21 and 22 and by moving the gyro-'17 and its giinbal ring 19 parallel to the trunnions-j20 the roller 31 turns the spur pinion 30 relatively to the trunnion 20 for the'purpose of providing an adjustment for compensating the slow straying motion of the' o. The gimbal ring 19 is translated p ed' to the trunnion 20 by means of the screw 35 which rocks the lever 36 on its fulcrum 37, the upper end of the lever presing on a ball on the inside of the ring-19 on the axis of i ms t the trunnion. The lever 38 turns on a fulcrum 39, and its control spring 40 serves to keep the screw always in engagement with the lever 36.

If the gyro strays slowly in elevation round the trunnions 20 thereby elevatin the prisms 6 and lowering the ima e 0 the target in the field of view of t e rangefin er, a small motion of the screw 35 serves {9 bring the image back to the separating I provide a handle 41 keyed to one of the trunnions 20 to precess the" gyro quickly about the trunnion axis 18 and bring the rotor axis again ap roximately vertical, should it deviateconstrerably from the vertical from any cause. The fork 42 keyed t0 the shaft 43 can be turned by means of a handle engaging on a square end of the shaft 43, so that one of the prongs comes in contact with the cone 44 attached to the gyro case 17, thus causing the gyro to precess quickly round the trunnions 20. This adjustment is useful should the screw adjustment 35 reach either of the limits of its motion due to exceptionally large straying of the gyro.

The arrangement only the two end reflectors and as the ship rolls the image of a vertical mast becomes inclined to the vertical at the angle of heel,

and a slight error in halving is thenproduced at the sides of the field which may introduce an error in range. In order to avoid this error I may employ the type of eyepiece prisms which make the lower image the inverted image of the upper when in pro r coincidence.

- Instead o stabilizing only the end reflectors I may alternatively stabilize the whole of the optical parts, the inner frame carrying the same being pivoted on bearings at the two ends of the outer tube, the manner of stabilizing this inner frame being by toothed gear similar to that described above say by means of a s ur wheel attached to this inner frame an gearing with pinion 30 in Figure 1, or by an other suitable linkage. In such a case preferably arrange the eyepoint of the range-finder so that it falls on or near the axis about which the frame is stabilized. The eyeguard or face piece I attach to the outer tube. Alternatively I may also fix the eye lens to the outer tube.

Having now particularly described and ascertained the nature of my said invention, and in what manner the same is to be performed, I declare that what I claim is:--

1. A ran e finder for use on an angularly moving y, comprising optical elements, a stabilizing device free from forced oscillations in phase with the disturbing forces introduced by the oscillations of the .body and connections between the elements and illustrated stabilizes the device for moving a part of the elements relatively to the body to compensate for the effect of its angular movement on the field of view of the range finder.

2. A range finder for use on an an ularly moving body, comprising optical e ements adapted to partake of the angular movement of the body, optical elements in optical relation to said first named elements and mounted to move relatively to the body, a stabilizing device free from forced oscillations in phase with the disturbing forces introduced by the oscillations of the bod and connections between the device 'an the movable optical elements for moving them relatively to the body to compensate for the effect of its angular movement on the field of view of the range finder.

3. A range finder for use on an angularly moving body, comprising optical elements mounted to move relatively to the bod a stabilizing device free from forced osc' lations in phase with the disturbing forces introduced by the oscillations of the body, connections between the elements and the device for moving the elements relatively to the body to compensate for the effect of its angular movement on the field of view of the range finder and axial means for roducing angular adjustment between the evice and the optical elements-stabilized thereby.

4. A ran e finder for use on an angularly moving b comprising optical elements, and connections between the elements and the gyroscope for moving a portion of the elements relatively to the body to compensate for the effect of its angular movement on the field of view of the range finder.

5. A range finder for use on an angularly moving body, comprising optical elements adapted to partake of the angular movement of the body, optical elements mounted to move relatively to the body'and associated with said first named elements, and connections between the gyroscope and thelast named optical elements for moving them relatively to the body to compensate for the effect of its angular movement on the field of view of the range finder.

6. A ran e finder for use on an an larly moving bo y, com rising optical e ements mounted to move re atively to the body, connections between the elements and the scope for moving the elements relative to the body to compensate for the effect 0 its.

angular movement on the field of view of the range finder and axial means for producing angular adjustment between the device and the optical elements stabilized thereb 7. A range finder for use on an angular y moving body, comprising a support, optical elements mounted on the bsgpport for movement relatively to the a gyroscope mounted on the support on mutually perpendicular axes, connections between the gyroscope and the optical elements for moving the latter relatively to the body to compensate for the efiect of its angular movement on the field of view of the range finder and means for moving the gyroscope parallel to one of-its supporting axes for effecting adjustments between the gyroscope and the optical elements stablized thereb 8.- A range finder for use on an angularly moving body, comprising optical elements mounted to move with the body, optical elements mounted to move relatively to the body, a gyroscope, connections between the gyroscope and the last named optical elements for moving the latter relatively to the'body to compensate for the 'efi'ect of its angular movement on the field of view of the range finder and means for controlling the position of the rotor axis of the gyroscope. 9. A rangefinder for use on an angularly moving body, comprising a support, optical elements mounted on the support for move ment relatively to the body, a gyroscope mounted upon axes on the support, connections between the gyroscope and the optical 10. A range finder for use on an angularly' moving bod comprising a-support, optical elements mounted on the sufport for move-' ment relatively to the ha y, a gyroscope mounted on the support on mutually perpendicular axes, connections between the gyroscope and the optical elements for moving the latter relatively tothe body to compensate for the effect of its angular movement on the field of view of the instrument stabilizin and means for producing precession of the gyroscope about each of its supporting axes.

11. A lglollfe finder for use on an angularly moving comprising a prism system mounted to move relatively to the body, opticalelements associated with said rism system and mounted to move with the body, a gyroscope and connections between the prism system and the gyroscope for movingthe system through an angle corresponding to the angle of movement of the platform to com ensate for the effect of the movement of t e platform upon the image of an object in the field of view of the range finder.

12. In a range finder for use on an arm gular moving body and having objectives, eye-piece prisms and reflecting prisms, a. casing, a member associated with the casing and carrying the objectives and .eyeiece prisms, members movably mounted within the casing and carrying the reflecting prisms, a gyroscope and connections between the gyroscope and the movably mounted members for moving the members and the prisms carried thereby relatively to the casing and the member which carries the objectives and eye-piece prisms to compensa e for the effect of the an ular movement of the body on the field of new of the range finder.

flu

13. A range finder for use on an ,angular- -ly moving body, comprising opticalelernents mounted to move relatively to the bod a device free from forced osc llations in ass with. the disturbing forces introduce by the oscillations of the body and connections between the device and the o tical elements for communicating to said elements a fraction of the relative movement between the device and the body.

JAMES BLAoKLooK- HENDERSON. 

